Wifi Connection Issues....access Point?

A couple of days ago I was sitting in my office and suddenly lost my wifi connection on both of my office computers.

The main office computer is hardwired and still has internet. I connect off of that through wirelessly.

When I try to connect it says network settings have changed or that the password is incorrect (which it is not). A diagnosis says there is an issue with the access point.

Have unplugged the router a couple of times and reset my computer but am not making any headway. Any suggestions?

My computer is a Lenovo G-50 notebook, model 80E5, running windows 10.

 

Has the Lenovo just been upgraded to Win 10 version 1803 or has it been on 1803 for a while? (Type winver in the desktop search box)

 

If it's router password issue, you can look at some router default username and password list, after you reset the router, try LAN connection first, sometimes WIFI is not turned on if you reset it.